Firing tool with ammunition, more particularly for use as a pin driving tool



2,984,836 ULARLY May 23, 1961 w. scHl-:NKEL

FIRING TOOL WITH AMMUNITION, MORE PARTIC FOR USE AS A PIN DRIVING TOOL am as n we: um.

FIRING TOOL WITH AMNIUNITION, MGRE PAR- TICULARLY FR USE AS A PIN DRIVING TOOL Willi Schenkel, Zurich, Switzerland, assignor to Novotech Anstalt, Schaan, Furstentum, Liechtenstein Filed Aug. 7, 1957, Ser. No. 676,775

2 Claims. (Cl. 1 445) In known tiring tools whcrein the bore is widened at the rearward end in order to accommodate the cartridge and is closed by a movable breech block, it often proves difficult, after a shot has been fired, to remove the empty cartridge case from the cartridge chamber formed by the aforesaid widening, since jamming occurs if the bore of the cartridge chamber is not quite clean or is otherwise unsatisfactory. A two-part construction of the cartridge chamber, which is often provided to permit the forcible extraction of the cartridge case and wherein one part is displaceable and is constructed as an injector, has the disadvantage, more particularly when small-calibre cartridges are used, that the pressure generated by the explosion fractures the wall of the case in the vicinity of the joints between the abutting cartridge chamber par-ts, whereby firstly the explosion gases issuing through the joints cause undesirable soiling, and secondly the cartridge case becomes `so tigh-tly jammed that it tears when the ejector is operated, since the cartridge base rim against which the ejector -acts cannot withstand forces of the intensity necessary in such cases. The attempt to provide more advantageous conditions by keeping the ejector as small as possible has also been unsuccessful, `since in that case the zone over which the ejector acts on the cartridge base rim has a correspondingly smaller periphery, so that the part of the rim which is affected is in some cases torn away from the case when the ejector is operated, since, especially with small-calibre cartridges which are `deep-drawn from Athin material, neither the cartridge base nor the side walls are strong enough to withstand such stresses. Cartridge cases which become jammed in this way have then to be removed by extraneous means, often resulting in damage to the tiring tool in addition to wasting time `and energy.

In the case of certain ring tools, such as are known more particularly for kdriving fastening pins, the cartridge is situated in a cylinder which is inserted in a rearward widening of the barrel. In this case 4this cylinder is generally removed after each shot is tired, and then the cartridge case is ejected from the cylinder from the front by means of a rod. Here also jamming may occur if the cartridge chamber bore is not absolutely clean. However it Vis possible to interchange the cylinder and to continue operations without losing any time. But this .construction has the disadvantage that the explosion gases may pass through the space between the cylinder V and the widened portion of the barrel towards the breech block and into the rear .parts of the tiring device. This causes harmful soiling vand gas losses. The drop in pressure in the barrel bore which is caused by the said losses has the lresult that the charge, which in such firing tools is Yadjusted accurately ito the actual work to be done, Ais Ynot utilised to the predetermined extent so that the pins do not impinge Vwith the `predetermined amount of force .on ,fthe artiC-,le into which they are tired.

-In 4order to make it possible for the cylinder t0 be used further without loss .of time even in cases where 2,984,836 Patented May 23, 1961 the cartridge case has jammed, the said cylinder has also been constructed so as to comprise two or more parts, but this requires very great accuracy during manufacture, and very close tolerances must be observed, and this is uneconomical. Also such divided cartridge chambers are awkward to use and there is always a risk of the cartridge case wall bursting in the region of the joints in lthe chamber pants, more especially when small-calibre cartridges are used. Y

The present invention overcomes all `these defects and relates -to -a tiring device with ammunition, wherein the barrel is widened at its rearward end vin order to accommodate ammunition andis closed by a movable breech block. The invention resides in that the ammunition consists of jacketed cartridges, the jacket having its maximum diameter `at a cross-section situated forwardly of its central portion and the contour of the jacket portion situated forwardly of the said ,cross-section is adapted to the widened rear portion of the barrel whereas on the contrary the jacket portion situated rearwardly of this crosssection is adapted in contour to a forwardly open recess situated in the breech block, the jacket tapering from `the aforesaid cross-section towards both ends with such differences in contour that, as a result of the two contours having different gripping capacity, when the breech block is pushed back after loading, the said jacket, adhering in the breech block, is .automatically pulled out of the widened portion ofthe barrel.

The jacket is expediently made of a synthetic plastic materialwhich has the property of providing a reliable seal between the jacket and the jacket housing formed by the widened portion of the barrel. Owing to its elasticity, a jacket of this kind will be widened slightly in an elastically yieldable fashion after detonation, owing to the explosion pressure, and bears against the wall of the widened portion of the barrel o n all sides, but at the same time it also acts as a shock-absorbing cushion between the cartridge case and the barrel, so that hard impacts against the wall of the widened portion of the barrel are prevented. vMore particularly, with tiring tools for driving pins into articles, wherein the tiring device and ammunition are constructed in the manner hereinbefore described, there is the advantage that the calibre of the jacket can optionally be made smaller than the calibre of the barrel, so that small-calibre ammunition can be .used with advantage. In any case, the jacketing of the cartridge allows a certain amount of freedom in the gradation of calibres. When one .bears in mind the very different dimensions of barrel calibre in tiring tools for driving pins into articles, the barrel calibre differing very greatly in accordance with the sizeof pin being used, the fact that the cartridge chamber calibre in such devices is dependent to a considerable extent on the barrel calibre, is very detrimental, since in the majority of cases large-calibre cartridges have to be used and these are considerably more expensive than small-calibre cartridges. As compared with this, the jacketing of a small-calibre cartridge is much cheaper, since neither the material costs nor the manufacturing costs of such a jacket are considerable, and in addition mass production is quite possible. The ammunition k.can be marketed with the cartridge already in its jacket, and after use the empty cartridge case can be thrown away with the jacket since it is scarcely worth while ejecting the case from ,the jacket in order to be able to use the jacket again, which would actually be possible as tests have shown. Y

After the breech is opened, there is no difficulty in ejecting the cartridge case and its jacket from the breech block, and ejection can be carried out mechanically and automatically.

In addition to being suitable for pin driving tools, the subject of the invention is also particularly well adapted 11 of the breech block recess.

aas/nase for use in ring devices employed in slaughtering work, and in small-calibre weapons of all kinds.

Examples of'embodiments of theinvention used in a lfiring device for driving pins into articles are illustrated in the drawings wherein:

Figs. 1 and 2 are longitudinal central sectional views illustrating the loaded condition, with the rear handle in different rotated positions.

Fig. 3 is a View similar to Fig. l, with the barrel removed from the breech block.

Fig. 4 is a cross-sectional view taken on the line IV-IV of Fig. 3.

' Figs. 5 to 8 each show a particular form of embodiment of the ammunition with the jacket shown in longitudinal central sectional view.

. As Figs. 1 and 2 show, the tiring tool comprises a barrel 1 whose bore has at its rear end a conically widened portion 2 to accommodate ammunition. The ammunition consists of a jacketed cartridge 3, the jacket having its maximum diameter at a cross-section situated forwardly of its central portion. The jacket portion 4 situated in front of this diameter is in the form of a hollow truncated cone matching the contour of the widened portion 2. The jacket portion 5 which is situated rearwardly of the afore- Asaid cross-section is fashioned in the manner of a hollow yof a hard-elastic synthetic plastic material which bears with a tight t against the housing owing to the force t. The jacket portion 5 is formed internally at its rear end with a groove in which the laterally projecting base rim 8 of the cartridge 3 is sunk.

Behind the recess 6 the breech block comprises a central cylindrical aperture which adjoins the recess 6 and in which a plug 9 is mounted so as to be displaceable axially to a limited extent. For this purpose the plug is formed with a central collar 10 which is mounted with some axial clearance in a corresponding annular groove The wall bounding the annular groove 11 at the rear is formed of a threaded ring 12 which is screwed into a corresponding internal screwthreading of the breech block aperture. The plug 9 is provided with an eccentric axial bore in which a tiring pin 13 is mounted so as to be displaceable in the axial sense. When the device is in the loaded condition illustrated, the plug 9 s constrained to bear against the rear side of the jacket portion 5 and the cartridge base, this being ensured by appropriate adjustment of the threaded ring 1'2, so that no play exists between the said ring and the collar 10, the whole of the possible play being provided at the opposite side of the collar.

The rear end of the breech block is surrounded by an axially displaceable, cap-shaped handle 14 whose inner end wall is provided with a projection 15. The handle 14 is under the influence of a restoring spring 16 which is arranged inside the said handle and which is fashioned as a compression spring and the said handle is held nonpositively in the pushed-back end position shown in Figs. 1 and 2, in which it is secured against being pushed back further by means which are not shown in the drawings. The spring 16 is adapted to act at the same time as a torsion spring and its rear end portion 17 engages in a recess in the end of the handle 14, whereas its forward end portion 18 engages in a corresponding recess in the breech block. The spring is so pre-tensioned torsionally that when it is not influenced by other forces it holds the handle 14 nonpositively rotated into the one Vend position shown in Figs. 1 and 3, in which the projection 15 bears against a stop pin 19 which is mounted on the rear of the breech block. By turning the handle in the direction of the arrow 21 (Fig. 4), the handle can be adjusted relatively to the breech block into another rotated position, namely that shown in Fig. 2. The projection 15 is arranged eccentrically in such manner that in the secondmentioned rotated position the tiring pin 13, and in the other rotated position the free rear side of the plug 9, is situated in its axial path of movement so that by advancing the handle 14 relatively to the breech block it is possible to carry out selectively the operation of detonating the cartridge 3 when the breech is closed (Fig. 2), and the operation of ejecting the cartridge case when the breech is opened (Fig. 3), since in the latter case, as Fig. 3 shows, owing to the axial advance of the handle 14, the projection 15 pushes the plug 9 `forward into the forward end position and thus forcibly ejects the jacket 4, 5 together with the cartridge 3 from its housing in the breech block recess 6.

As is known in the case of such tiring devices, the breech is opened by screwing the barrel 1 out of the breech block, whereupon the jacket portion 4 is readily detached from its seat on the wall of the widened portion 2 of the barrel bore, since, as hereinbefore mentioned the angle of taper of the portion 4 is greater than that of the rear portion 5 of the jacket, which therefore has greater capacity for gripping against its seating surface than has the front portion 4 of the jacket.

After the jacketed cartridge is ejected, loading is carried out by rstly inserting a fastening pin 22 into the barrel bore lfrom the rear. This pin comprises at its rear end a guide surface 23 which corresponds to the barrel calibre and which comprises at the rear a base ring 24 with a laterally slightly projecting rim which comes to bear with a close tit in the `front end portion of the widened portion 2, when the pin is inserted from the rear into the barrel bore. Then the ammunition, in the form of the jacketed cartridge 3, is inserted either into the widened portion 2 of the barrel vor into the recess 6 of the breech block, -and the breech block is screwed on. The restoring spring 16 holds the rear handle 14 in the initial position shown in Fig. 1. In order to fire a shot,y

lthe barrel muzzle is placed against the predetermined part of the article into which the pin is to be tired. The operator grasps the -barrel `1 with one Ahand and in his other hand he holds the rear handle 14 and turns the latter in the direction of the arrow 21 (Fig. 4) into the other end position which is illustrated in Fig. 2 and in which the tiring pin lies in the path of the projection 15, so that when the handle 14 is pushed forward the cartridge is detonated, thus propelling the pin 22 as soon as the explosion force behind it has increased sutciently to overcome the braking action of the ring 24.

In the embodiment shown in Fig. 5, the jacket has the same shape as that shown in Figs. 1 to 3. Here the angle of taper a of the rear jacket portion 5 amounts to approximately 10, whereas the angle of taper of the front jacket portion 4 is more than 40. It is expedient to make the angle a not more than 15 and the angle at least 15. It is also expedient to make the rear jacket portion 5 lo'nger than the front portion 4. In the embodiment shown in Fig. 5, the rear jacket portion is rather more than twice as long as the front portion. In the embodiment illustrated in Fig. 8, this length ratio amounts to approximately '10:1, the angle being approximately and the angle a having approximately the same value as in the embodiment shown in Fig. 5.

The embodiment o'f Fig. 6 diiers from the embodiment of Fig. 5 essentially only in that the `front portion 4 of the jacket is stepped immediately in front of the largest jacket cross-section, in the form of a short sharply tapering cone 25, and merges after this step into a relatively gradual frusto-conical portion which has a sdmewhat smaller angle of taper than the angle according to Fig. 5, but which is substantially greater than the angle of agences taper of the rear portion 5, which again is approximately The embodiment of Fig. 7 diiers essentially from the embodiments already described in that the front portion of the jacket comprises a rounded end 26 whereas the rear portion 5 is constructed approximately similarly to the embodiments shown in Figs. 5 and 6.

In all the embodiments of jacket which are illustrated, the jacket tapers from a cross-section of maximum diameter towards both ends with such differences in contours that, owing to the resulting different gripping capacity of the two contours, when the breech block is pushed back after the tool has been loaded the said jacket, adhering in the breech block, is automatically withdrawn from the rear widened portion 2 of the barrel bore, so that when the breech is opened the jacket is mounted with its rear portion 5 in the recess 6 of the breech block. Consequently, when the breech is opened after each shot, the jacket together with the cartridge case can readily be removed by operating the ejecting means.

It is quite possi-ble, by way of modification of the embodiments shown in the drawings, to control the means for advancing the stud 9 in such manner in dependence on the movement of the breech block that the opening of the breech necessarily results in pushing the stud forward from the rear to the front end position.

What I claim is:

l. In a ring tool, in combination, a barrel formed with an axial bore which gradually increases in cross sectional area from a part of said bore located adjacent but forwardly of the rear end of the barrel up to the rear end of the barrel; a breech block connected to the barrel adjacent the rear end thereof for axial movement with respect thereto, said breech block extending rearwardly from the rear end of the barrel and being formed with an axial bore which is an extension o'f and coaxial with the barrel bore, said bore of said breech block having at its front end a cross sectional area substantially equal to the cross sectional area of the rear end of the bore of the barrel and said bore of said breech block gradually diminishing in cross sectional area rearwardly from the yfront end of the bore of the breech block through an axial distance greater than the axial distance of said part of said bore of said barrel from the rear end thereof, so that an ammunition jacket having an exterior contour matching that of said breech block bore and the barrel bore from said part thereof to the rear end of the barrel will be wedged into the breech block with a force greater than the force with which it engages the barrel so as to be retained by the breech block when the latter is moved axially away from the rear end of the barrel; an ejector plug located in said breech block ybore for axial movement therein land having at least a forward portion of no greater cross sectional area than the smallest crdss sectional area of said breech block bore located in the part of the breech block bore which is smallest in cross sectional area; and means cooperating with said breech block for advancing said plug forwardly after the breech block has been moved rearwardly away from the barrel to eject an ammunition jacket from the breech block, said plug being formed with a bore passing therethrough, and a firing pin located in said bore of said plug `for axial movement with respect thereto, said bore of said plug and said firing pin being radially olset with respect to the axis of said breech block bore, and said means for axially advancing said plug being in the form of a hollow cap member receiving a rear end portion of said breech block in its interior and being axially movable along said breech block, said cap member having an end wall provided with an inner forward face directed toward said plug and tiring pin and said cap member fixedly carrying on said face of said end wall thereof a projection extending forwardly toward said plug and also radially offset with respect to the axis of said breech block bore, said cap member being turnable with respect to said breech block to and from a position where said projection is aligned with said tiring pin so that forward movement of said cap member when it is in the latter position will actuate the ring pin, said cap member being movable Iforwardly when itis angularly displaced from said position to push said projection against said plug for advancing the latter to eject a jacket.

2. IIn a ring tool as recited in claim 1, spring means located in said cap member between said end wall thereof and said breech block for yieldably maintaining said cap member in a rear idle position where said projection is axially displaced rearwardly df said plug and tiring pin.

References Cited in the tile of this patent UNITED STATES PATENTS 2,811,901 Barr Nov. 5, 1957 2,931,039 Henning et al. Apr. 5, 1960 FOREIGN PATENTS 149,829 Sweden Apr. 26, 1955 371,716 Great Britain Apr. 28, 1932 922,994 Germany Jan. 31, 1955 

